Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;
import java.lang.ref.Reference;
import java.lang.reflect.Field;
import java.util.Arrays;
import org.springframework.core.NamedThreadLocal;

public class Main {
    public static void dumphreadLocals() {
        try {
            // Get a reference to the thread locals table of the current thread
            Thread thread = Thread.currentThread();
            Field threadLocalsField = Thread.class.getDeclaredField("threadLocals");
            threadLocalsField.setAccessible(true);
            Object threadLocalTable = threadLocalsField.get(thread);

            // Get a reference to the array holding the thread local variables
            // inside the
            // ThreadLocalMap of the current thread
            @SuppressWarnings("rawtypes")
            Class threadLocalMapClass = Class.forName("java.lang.ThreadLocal$ThreadLocalMap");
            Field tableField = threadLocalMapClass.getDeclaredField("table");
            tableField.setAccessible(true);
            Object[] table = (Object[]) tableField.get(threadLocalTable);

            @SuppressWarnings("rawtypes")
            Class threadLocalMapEntryClass = Class.forName("java.lang.ThreadLocal$ThreadLocalMap$Entry");
            Field entryValueField = threadLocalMapEntryClass.getDeclaredField("value");
            entryValueField.setAccessible(true);
            // The key to the ThreadLocalMap is a WeakReference object. The
            // referent field of this object
            // is a reference to the actual ThreadLocal variable
            Field referentField = Reference.class.getDeclaredField("referent");
            referentField.setAccessible(true);

            for (Object entry : table) {
                // Each entry in the table array of ThreadLocalMap is an Entry
                // object
                // representing the thread local reference and its value
                if (entry != null) {

                    Object tlcValue = entryValueField.get(entry);

                    ThreadLocal threadLocal = (ThreadLocal) referentField.get(entry);

                    // System.out.println("thread local value "+tlcValue);
                    // if(threadLocal)
                    printObject(threadLocal, tlcValue);
                }
            }
            System.out.println("__________________________");
        } catch (Exception e) {
            // We will tolerate an exception here and just log it
            throw new IllegalStateException(e);
        }
    }

    @SuppressWarnings("rawtypes")
    private static void printObject(ThreadLocal threadLocal, Object obj) {
        String threadLocalCls = threadLocal.getClass().getName();
        if (threadLocal instanceof NamedThreadLocal) {
            System.out.print("......Spring threadlocal var: " + threadLocal + "=");
        } else if (obj == null || threadLocalCls.startsWith("java") || threadLocalCls.startsWith("sun")) {
            return;
        }
        if (obj instanceof Object[]) {
            System.out.println(Arrays.deepToString((Object[]) obj));
        } else if (obj instanceof java.lang.ref.Reference) {
            java.lang.ref.Reference ref = (Reference) obj;
            System.out.println(" ref " + ref.getClass().getName() + " ref to " + ref.get());
        } else if (obj instanceof ThreadLocal) {
            ThreadLocal threadLc = (ThreadLocal) obj;
            String clssName = threadLc.getClass().getName();
            System.out.println(threadLc.getClass().getName() + "=" + threadLc.get());
        } else {
            System.out.println(obj);
        }
    }
}